Low dusting crystal transformations of 2,2&#39;-methylenbis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol] and mixture thereof, method for preparing them, and ultraviolet absorbent using the same

ABSTRACT

The present invention relates to a low dusting crystalline 2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol] type I crystal transformation which exhibits diffraction peaks at diffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and 23.0° in powder X-ray diffraction analysis with Cu-Kα radiation; a low dusting 2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol] type II crystal transformation which does not exhibit a distinct diffraction peak but an amorphous halo in powder X-ray diffraction analysis with Cu-Kα radiation; a mixture thereof; a method for preparing them; and a UV light absorber, an emulsion composition and a polymer material using them.

TECHNICAL FIELD

[0001] The present invention relates to a low dusting crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation which is useful for ultraviolet (UV) lightabsorbers and a method for preparing the same. In addition, the presentinvention relates to a low dusting amorphous2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation which is different from theabove-mentioned crystalline transformation, and a method for preparingthe same. Further, the present invention relates to mixtures containingthese compounds and UV light absorbers using these compounds.

BACKGROUND ART

[0002] In recent years, the demand for additives such as flameretardants, antioxidants or UV light absorbers has been increasing witha frequent use of polymer products such as a variety of plastics,synthetic rubbers, nylon fibers or resin coatings. Particularly, inpromotion of differentiation of polymer products and making them highlyvalue added, it has become an important problem to use UV lightabsorbers in order to protect the polymer products against deteriorationphenomena due to UV light such as cracks or discoloration, and thereforea stable supply of UV light absorber is required. Representative UVlight absorbers include benzophenones, benzotriazoles, cyanoacrylates,salycylates and the like, and they are generally used by kneading intopolymer materials as they are, by adding to a coating or an oil, etc. orby preparing an emulsion composition thereof and allowing it to adsorbon fibers. A large number of UV light absorbers known hitherto areexcellent in efficiency of UV light absorption, but have problems suchas sublimation or volatilization when they are kneaded into polymermaterials and heated or processed, or problems that they are graduallyvolatilized and scattered when the finished products are used. In orderto overcome these problems, improvements such as a polymerization of UVlight absorbers or an addition of non-volatile functional groups theretohave been attempted, but none was proven to be fully satisfactory. Inaddition, when UV light absorbers in a polymerized state are handled ina shape of powder, most of them have problems such as dust scattering,low flowability or low shelf stability, and they are required to beimproved in powder properties.

[0003] It is generally known that2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]is effective as UV light absorbers for plastics, coatings, oil, fibersand the like.

[0004] The method of preparation of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]is disclosed in Japanese Patent Laid-open No. Sho 61-115073 in which4-(1,1,3,3-tetramethyl)butyl-6-benzotriazol-2-yl phenol is reacted witha dialkylamine and formalin to give a Mannich base, and a reaction crudeproduct obtained upon treating the resulting Mannich base with a base iscrystallized from heptane, in Japanese Patent Laid-open No. Hei 4-29087in which 4-(1,1,3,3-tetramethyl)butyl-6-benzotriazol-2-yl phenol isreacted with a dialkylamine and formalin to give a Mannich base, and areaction crude product obtained upon treating the resulting Mannich basewith a base is crystallized from xylene, or in Japanese Patent Laid-openNo. Hei 5-213908 in which4-(1,1,3,3-tetramethyl)butyl-6-benzotriazol-2-yl phenol and formalin arereacted with concentrated sulfuric acid to give a reaction crude productand the resulting crude product is crystallized from methanol.

[0005] However, these patent publications do not describe powderproperties such as scattering, flowability or stability on storage ofsolid-like substances obtained by the method disclosed therein, norcrystalline state of the solid-like substances. Further, only the use ofmethanol, xylene or heptane as solvent for crystallization is describedin examples of the above-mentioned patent publications.

[0006] On the other hand, it is generally known that there occursproblems such as dust scattering, low flowability or concretion onstorage when the solid-like substances are handled. In order to solvethese problems, various investigations are undertaken on crystallinestate of the solid-like substances. For example, Japanese PatentLaid-open Nos. Hei 6-128195 and Hei 6-72960 disclose that there aredifference in bulk specific gravity, particle size distribution andflowability of powders in each crystal transformation for the samecompound. As mentioned above, it is known that even if two compoundsbelong to the same compound, they are different from each other infunctionality or physical properties depending on in what crystal statethey are. It is important to obtain such an information for a tendencyin order to heighten the added value of products and an improvement inquality thereof. In addition, as practical methods for analyzingsubstances from the view point of crystal, X-ray diffraction analysisand differential scanning calorimeter analysis are used in variousfields such as differentiation of crystal states or development of newfunctional materials.

[0007]2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]prepared by the known methods is in a form of fine powder, and causesproblems in workability such as scattering or partial agglomerate of thepowder during handling including weighing in drying step or packagingstep and feeding. Thus, it is desired to provide solid with goodflowability which does not affect adversely workability in handling ofthe powder.

[0008] The object of the present invention is to provide a low dustingcrystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and a low dusting amorphous2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation which have excellent UV light absorptivepower, exert little sublimation or volatilization, are easy to handleand excellent in workability at use, and cause little dust; methods forpreparing these compounds, mixtures containing these compounds and UVlight absorbers using these compounds.

DISCLOSURE OF INVENTION

[0009] 1) A first aspect of the present invention relates to a lowdusting crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation (this crystal transformation ishereinafter referred to also as “type I crystal transformation”) offormula (1)

[0010] which exhibits diffraction peaks at diffraction angles (2θ±0.1°)of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and 23.0° in powder X-ray diffractionanalysis with Cu-Kα radiation.

[0011] 2) A second aspect of the present invention relates to thecrystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation as set forth in the above-mentioned 1),which has a compaction degree of 35 or less in powder test.

[0012] 3) A third aspect of the present invention relates to a methodfor preparing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation as set forth in the above-mentioned 1) or2), characterized by crystallizing2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]in the presence of ketone.

[0013] 4) A fourth aspect of the present invention relates to2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation (this crystal transformation ishereinafter referred to also as “type II crystal transformation”) offormula (1)

[0014] characterized in that does not exhibit a distinct diffractionpeak but a halo in powder X-ray diffraction analysis with Cu-Kαradiation and that is amorphous.

[0015] 5) A fifth aspect of the present invention relates to a mixtureof2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]comprising2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation which exhibits diffraction peaks atdiffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and23.0° in powder X-ray diffraction analysis with Cu-Kα radiation, and the2,2′-methylenebis[4-(1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation as set forth in the above-mentioned 4) inan amount of 1% by weight or more based on the amount of the type Icrystal transformation.

[0016] 6) A sixth aspect of the present invention relates to a mixtureof2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]comprising the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation as set forth in the above-mentioned 1) or2), and the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation as set forth in the above-mentioned 4) inan amount of 1% by weight or more based on the amount of the type Icrystal transformation.

[0017] 7) A seventh aspect of the present invention relates to a methodfor preparing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation as set forth in the above-mentioned 4),characterized by melting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]at a temperature of 195° C. or more, and cooling and solidifying.

[0018] 8) An eighth aspect of the present invention relates to a methodfor preparing the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as set forth in the above-mentioned 5) or 6), characterized by melting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]at a temperature of 195° C. or more, and cooling and solidifying.

[0019] 9) A ninth aspect of the present invention relates to a UV lightabsorber characterized by containing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation as set forth in the above-mentioned 1) or2).

[0020] 10) A tenth aspect of the present invention relates to anemulsion composition characterized by containing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation as set forth in the above-mentioned 1) or2).

[0021] 11) An eleventh aspect of the present invention relates to apolymer material characterized by containing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation as set forth in the above-mentioned 1) or2) or the emulsion composition as set forth in the above-mentioned 10).

[0022] 12) A twelfth aspect of the present invention relates to a UVlight absorber characterized by containing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation as set forth in the above-mentioned 4).

[0023] 13) A thirteenth aspect of the present invention relates to anemulsion composition characterized by containing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation as set forth in the above-mentioned 4).

[0024] 14) A fourteenth aspect of the present invention relates to apolymer material characterized by containing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation as set forth in the above-mentioned 4) orthe emulsion composition as set forth in the above-mentioned 13).

[0025] 15) A fifteenth aspect of the present invention relates to a UVlight absorber characterized by containing the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as set forth in the above-mentioned 5) or 6).

[0026] 16) A sixteenth aspect of the present invention relates to anemulsion composition characterized by containing the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as set forth in the above-mentioned 5) or 6).

[0027] 17) A seventeenth aspect of the present invention relates to apolymer material characterized by containing the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as set forth in the above-mentioned 5) or 6) or the emulsion compositionas set forth in the above-mentioned 16).

[0028] As mentioned above,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]prepared by a known method is in a form of fine powder, and causesproblems in workability and working environment such as scattering ofdust during handling.

[0029] As a result of several investigations, the present inventorsfound that2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation prepared by the method according to thepresent invention has an excellent UV light absorptive power, exertlittle sublimation or volatilization, are easy to handle and excellentin workability at use, and cause little dust, and consequently reached aresolution of the problems.

[0030] In addition, the present inventors found that substances obtainedby melting, cooling and solidifying2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]prepared by a known method or2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to the present invention alsoare in a state of solid causing little dust, and have an inherentability as UV light absorber, in particular an excellent UV lightabsorptive power when they are used in a state where an emulsioncomposition therefrom is adsorbed on a fiber, and consequently reached aresolution of the problems.

[0031] In general, changes in physical properties for the same compounddepending on crystallization condition seldom occur and do not arise inall compounds. Therefore, the above-mentioned changes in the presentinvention are a specific property for2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol].In addition, there exists no information on the crystal analysis of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]until now. Thus, the results of the present invention can not be easilyfound.

[0032] Further, the present inventors conducted powder X-ray diffractionanalysis with Cu-Kα radiation for2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and type II crystal transformation inorder to make the characteristics of these crystals clearer. As aresult, it was found that the low dusting type I crystal transformationof the present invention has diffraction peaks at diffraction angles(2θ±0.1°) of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and 23.0° (see, FIG. 1), onthe other hand the type II crystal transformation of the presentinvention is amorphous and does not exhibit a distinct diffraction peakbut a halo (see, FIG. 2).

[0033] Hereinafter, the present invention will be explained in detail.

[0034] First of all, the present inventors obtained crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation causing little dust by crystallizing areaction product of 4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenolof formula (2), dialkylamine, formaldehyde and a base. in the presenceof ketone.

[0035] Next, the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation obtained according to the above-mentionedprocedure was subjected to powder X-ray diffraction analysis with Cu-Kαradiation. As a result, it was found that the type I crystaltransformation is a substance with a good crystallizability anddiffraction peaks at diffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°,16.1°, 18.1° and 23.0° in the powder X-ray diffraction analysis (FIG. 1is a powder X-ray diffraction pattern of the substance).

[0036] Further, the present inventors measured the compaction degree ofthe crystalline powder of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation obtained according to the presentinvention with powder test. As a result, it was found that thecrystalline powder has a compaction degree ranging from 28 to 35 on theaverage which is lower than that ranging from 45 to 48 in theconventional fine powder produced from the same compound by using xyleneor the like and that the crystalline powder has a high flowability.

[0037] Generally, the compaction degree in powder test has been known asa factor most closely related to the flowability of powder, and it issaid that the lower the measured value of a powder is, the higher theflowability thereof is, and that powders having a compaction degree of40 or more have an undesirable flowability. From the fact, it is clearthat the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation of the present invention has moreflowability than2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]prepared by using xylene or the like in the prior art.

[0038] The ketone solvents used in the crystallization of the lowdusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation of the present invention include acetone,methyl ethyl ketone, methyl isobutyl ketone and the like, and they maybe used alone or as a mixed solvent. Further, the solvents may be usedas a mixed solvent with alcohols such as methanol, isopropyl alcohol,n-butanol, cyclohaxanol, ethylene glycol or propylene glycol, water,ethers such as dioxane, dibutyl ether, ethylisoamyl ether or ethylphenylether; hydrocarbons such as n-decane, 3-ethylhexane, methylcyclohexane,toluene, ethylbenzene, cumene, o-cymene, p-cymene, m-cymene, o-xylene,m-xylene, p-xylene, t-butylbenzene, 1-butyl-4-methylbenzene,1-butyl-2-methylbenzene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene,1,3,5-trimethylbenzene or 1,2,4,5-tetramethylbenzene; carboxylates suchas butyl acetate or ethyl propionate; organic halides such as carbontetrachloride, chlorobenzene or o-dichlorobenzene; nitrogen-containingcompounds such as dimethylformamide, dimethylacetamide, quinoline,n-butylamine or 2-methyl pyrrolidone. They can be used under not only anormal pressure but also a reduced pressure or a pressure.

[0039] The condition under which the solvent is used is not specificallylimited, but it is natural that the yield is greatly influenced by thesolubility.

[0040] Further, the present inventors conducted several investigation onthe type II crystal transformation of the present invention, and foundthat the type II crystal transformation can be prepared as a solid withlittle dust by melting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained by a known method or the low dusting type I crystaltransformation of the present invention at a temperature of 195° C. ormore and then cooling and solidifying, and that the solid can be easilyobtained also as a substance in a flake form by using a flaker or thelike. In the meantime, depending on the condition of heating process,the above-mentioned type I crystal transformation may be obtained inaddition to the type II crystal transformation. For example, in a casewhere the heating process is conducted at about 200° C., a mixture ofthe type I crystal transformation and the type II crystal transformationcan be prepared. In the mixture, the type II crystal transformation iscontained in an amount of 1% by weight or more, and the mixture can bealso obtained in a solid form with little dust.

[0041] Powder X-ray diffraction analysis may not show apparentdifference in diffraction pattern between the mixture of the type Icrystal transformation and type II crystal transformation in a mixingproportion prepared according to the present invention and 100% type Icrystal transformation. However, the mixing proportion of the type Icrystal transformation and the type II crystal transformation can beclarified by conducting a measurement with differential scanningcalorimeter (TA Instrument Type 2920 DSC, sample amount of 1.3 mg,atmosphere in the oven of nitrogen flow with 50 ml/min., and heatingrate at 10.0° C./min., hereinafter referred to as DSC).

[0042] In the DSC measurements, 100% type I crystal transformation showsan endothermic peak at around 200° C. due to melting and 100% type IIcrystal transformation shows an exothermic peak at around 130° C. (dueto transition from type II to type I) and an endothermic peak at around200° C. (due to melting of type I after the transition). Therefore, themixing proportion of type II and type I based on the DSC measurements isdetermined by using a calibration curve prepared from calorimetric ratioof the exothermic peak of type II and the endothermic peak of type Iwhich are measured with respective pure crystal transformation.

[0043] That is, the present invention can provide an amorphous type IIcrystal transformation which do not exhibit a distinct diffraction peakbut a halo in powder X-ray diffraction with Cu-Kα radiation, and amixture of type II and type I, in both a solid form with little dust bymelting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]or the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation of the present invention with no solventor a solvent at a normal pressure or under a reduced pressure or apressure at a temperature of 195° C. or more, preferably a temperatureranging from 200° C. to 250° C. and then cooling. In addition, asubstance in a flake form can be easily obtained by using a flaker orthe like.

[0044] The solvent which may be present in the preparation of the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation of the present invention includes water,and alcohols such as n-butanol, cyclohaxanol, ethylene glycol orpropylene glycol, ethers such as dioxane, dibutyl ether, ethylisoamylether or ethylphenyl ether; hydrocarbons such as n-decane,3-ethylhexane, methylcyclohexane, toluene, ethylbenzene, cumene,o-cymene, p-cymene, m-cymene, o-xylene, m-xylene, p-xylene,t-butylbenzene, 1-butyl-4-methylbenzene, 1-butyl-2-methylbenzene,1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzeneor 1,2,4,5-tetramethylbenzene; carboxylates such as butyl acetate orethyl propionate; ketones such as methyl ethyl ketone or methyl isobutylketone; organic halides such as carbon tetrachloride, chlorobenzene oro-dichlorobenzene; nitrogen-containing compounds such asdimethylformamide, dimethylacetamide, quinoline, n-butylamine or2-methyl pyrrolidone, and the solvent may be used alone or as a mixedsolvent.

[0045] The low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and type II crystal transformation of thepresent invention can be mixed into polymer materials as UV lightabsorber in the usual way in a powder form, a flake form, a suspensionor an emulsion composition. The polymer materials include resincompositions, fibers, rubber, paper and the like, and particularly anemulsion composition effective for dyeing is often used for fibers.Examples of the resin compositions are phenol resins, melamine resins,epoxy resins, polyurethane, polyimide, vinyl chloride, polyvinylacetal,polyethylene, polypropylene, polybutylene, polymethylpentene,polystyrene, polybutadiene resins, ethylene-propylene copolymers,ethylene-vinyl acetate copolymers, ethylene-methyl (ethyl) acrylatecopolymers, polyester, acrylonitrile-styrene resins (AS),acrylonitrile-butadiene-styrene resins (ABS), polyethylene terephthalate(PET), polybutylene terephthalate, polycarbonate (PC), PC.ABS alloy,PC.PET alloy, polyphenylene ether resins, polyphenylene sulfide resins,methacrylate resins, polyamide resins, diallyl phthalate resins,silicone resins, unsaturated polyester or the like, and they can be usedas polymer material with excellent weatherability for automobile relatedparts, OA equipment, electronic parts, household appliance, machineparts, building parts, medical accessory parts, household miscellaneousgoods and the like.

[0046] The low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and type II crystal transformation, andthe mixture of type I crystal transformation and type II crystaltransformation of the present invention can be added to a resin and soforth alone to exert an effective UV light absorptive power therebymaking possible to prevent deterioration in quality, or can be also usedin combination with antioxidants or light stabilizers that are known inthe prior art, or can be mixed with hygroscopic agents, mildew-proofingagents, antifoaming agents or the like.

[0047] The emulsion composition containing the low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation or type II crystal transformation, or themixture of type I crystal transformation and type II crystaltransformation according to the present invention can prepared byemulsifying the low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation or type II crystal transformation, or themixture of type I crystal transformation and type II crystaltransformation optionally with additives of common use in the presenceof emulsifying agents with the use of a machine for emulsifying anddispersing, such as a homogenizer, a colloid mill or a bead mill.Various surfactants can be used as the emulsifying agent without anylimitation, and hygroscopic agents, mildew-proofing agents, antifoamingagents, antioxidants, light stabilizers or the like may be mixed as theadditives of common use.

[0048] Concrete examples of the emulsifying agent that can be used inthe present invention are anionic surfactants such as sodium stearate,sodium lauryl sulfate, sodium lauryl ether sulfate, sodium dodecylbenzene sulfonate or di-2-ethylhexyl sodium sulfosuccinate; cationicsurfactants such as alkyltrimethyl ammonium chloride or triethanolaminemonostearate formate; amphoteric surfactants such as sodiumlaurylaminopropionate; and non-ionic surfactants such as polyethyleneglycol lauric acid monoester, polyethylene glycol lauric acid diester,polyoxyethylene stearate, diethylene glycol monooleyl ether or glycerinlauric acid monoester, and they can be alone or in a mixture thereof.

[0049] The hygroscopic agent which can be mixed into the emulsioncomposition or polymer material of the present invention includes forexample propylene glycol, ethylene glycol, d-sorbitol or urea.

[0050] The mildew-proofing agent which can be mixed into the emulsioncomposition or polymer material of the present invention includes forexample p-hydroxy benzoic acid or chloroacetamide.

[0051] The antifoaming agent which can be mixed into the emulsioncomposition or polymer material of the present invention includes forexample silicones such as silicone resin, or organic polar compoundssuch as 2-ethylhexanol or polypropylene glycol.

[0052] The antioxidants which can be mixed into the emulsion compositionor polymer material of the present invention includes for example2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol,2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol,2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol,2-(α-methylcyclohexyl)-4,6-dimethylphenol,2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol,2,6-dinonyl-4-methylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol,2,4-dimethyl-6-(1′-methyl-undeca-1′-yl)phenol,2,4-dimethyl-6-(1′-methyl-trideca-1′-yl)phenol and a mixture thereof;2,4-dioctylthiomethyl-6-tert-butylphenol,2,4-dioctylthiomethyl-6-methylphenol,2,4-dioctylthiomethyl-6-ethylphenol,2,6-didodecylthiomethyl-4-nonylphenol and a mixture thereof;2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone,2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol,2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyphenylstearate,bis(3,5-di-tert-butyl-4-hydroxyphenyl)adipate and a mixture thereof;2,4-bisoctylmercapto-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine,2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate,2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine,1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate or the like and2,2′-methylene bis(6-tert-butyl-4-methylphenol), 2,2′-methylenebis(6-tert-butyl-4-ethylphenol), 2,2′-ethylidenebis(4,6-di-tert-butylphenol), 2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol), 4,4′-methylenebis(2,6-di-tert-butylphenol), 4,4′-methylenebis(6-tert-butyl-2-methylphenol),1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, ethylene glycolbis[3,3′-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate] or the like, and1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol or the like.

[0053] The light stabilizers which can be mixed into the emulsioncomposition or polymer material of the present invention includes forexample benzotriazoles such as2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2-hydroxyphenyl)benzotriazole,2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-[2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl] benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chlorobenzotriazole,2-(2′-hydroxy-4′-octoxyphenyl)benzotriazole,2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole or2-[3′-tert-butyl-2′-hydroxy-5′-(n-octyloxycarbonylethyl)phenyl]-5-chlorobenzotriazole;benzophenones such as 4-hydroxy-, 4-methoxy-, 4-octoxy-, 4-decyloxy-,4-dodecyloxy-, 4-benzyloxy-, 4,2′,4′-trihydroxy-,2′-hydroxy-4,4′-dimethoxy- or 4-(2-ethylhexyloxy)-2-hydroxybenzophenone; salicylates such as 4-tert-butylphenyl salicylate, phenylsalicylate or octylphenyl salicylate; resorcinols such as dibenzoylresorcinol, bis(4-tert-butylbenzoyl resorcinol) or2,4-di-tert-butylphenyl resorcinol; benzoates such as3,5-di-tert-butyl-4-hydroxybenzoate orhexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; acrylates such as ethylα-cyano-β,β-diphenyl acrylate or isooctyl α-cyano-β,β-diphenylacrylate;cinamates such as methyl α-carbomethoxy cinnamate or methylα-cyano-β,β-methyl-p-methoxy cinnamate; acid esters such asbis(2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(2,2,6,6-tetramethyl-4-piperidyl)succinate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate,bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate orbis(1,2,2,6,6-pentamethyl-4-piperidyl)adipate; oxanilides such as4,4′-dioctyloxyoxanilide, 2,2-diethoxyoxyoxanilide,2,2′-dioctyloxy-5,5′-di-tert-butyloxanilide,2,2′-didodecyloxy-5,5′-di-tert-butyloxanilide,2-ethoxy-2′-ethyloxanilide, N,N′-bis(3-dimethylaminopropyl)oxanilide or2-ethoxy-5-tert-butyl-2′-ethoxyoxanilide; triazines such as2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0054]FIG. 1 shows an X-ray diffraction pattern for the low dustingcrystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation prepared in Example 1 according to thepresent invention;

[0055]FIG. 2 shows an X-ray diffraction pattern for the amorphous2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]which is a novel type II crystal transformation prepared in Example 3according to the present invention;

[0056]FIG. 3 shows a DSC chart for the novel type II crystaltransformation prepared in Example 3 according to the present invention;

[0057]FIG. 4 shows an X-ray diffraction pattern for the compoundprepared in Comparative Example 2 according to a conventional process;

[0058]FIG. 5 shows a DSC chart for the compound prepared in ComparativeExample 2 according to a conventional process;

[0059]FIG. 6 shows an X-ray diffraction pattern for the mixture of typeI crystal transformation and type II crystal transformation prepared inExample 4 according to the present invention;

[0060]FIG. 7 shows a DSC chart for the mixture of type I crystaltransformation and type II crystal transformation prepared in Example 4according to the present invention;

[0061]FIG. 8 shows an X-ray diffraction pattern for the mixture of typeI crystal transformation and type II crystal transformation prepared inExample 5 according to the present invention;

[0062]FIG. 9 shows an X-ray diffraction pattern for a sheet made byusing the compound prepared in Example 3 (100% type II) as lightstabilizer; and

[0063]FIG. 10 shows an X-ray diffraction pattern for a sheet made byusing the compound prepared in Comparative Example 2 (100% type Iaccording to a conventional process) as light stabilizer.

BEST MODE FOR CARRYING OUT THE INVENTION

[0064] Hereinafter, the present invention is described based on examplesto which the present invention is not limited at all.

[0065] I. Preparation and evaluation of low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation

[0066] Condition and Method for Measurement

[0067] Powder X-ray diffraction analysis with Cu-Kα radiation wasconducted with TFD-18kw manufactured by Mac Science Co., Ltd. under thecondition of anti-cathode Cu-Kα (1.5405 Å), 40 kV-50 mA and a scanningrate at 2.000°/min. In addition, a diffraction angle (2θ) in powderX-ray diffraction analysis for the same crystal form is identical withan error of about ±0.1°, and therefore clearly indicates a difference incrystal transformation. The relative intensity of a diffractionradiation may effect change in the intensity ratio depending on theparticle diameter of the sample to be measured.

[0068] Powder test was conducted with Hosokawa Micron Powder TesterTYPE-E and a 100 cc cylinder container with a diameter of 5 cm was usedfor determination of an apparent specific gravity.

[0069] The measurement of loose apparent specific gravity was conductedby gently filling the container to an overflowing point with the powder,weighing the powder after leveling off any extra powder above thecontainer surface, and determining the loose specific gravity bydividing the weight (g) of the powder by 100.

[0070] The measurement of dense apparent specific gravity was conductedby filling the container with the powder in a similar manner as in theloose apparent specific gravity, tapping 180 times, then weighing thepowder after leveling off any extra powder above the container surface,and determining the dense apparent specific gravity by dividing theweight (g) of the powder by 100. In addition, compaction degree wascalculated according to the equation below:

Compaction degree=100(P−A)/P

[0071] wherein A is a loose apparent specific gravity and P is a denseapparent specific gravity.

EXAMPLE 1 Preparation of low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation

[0072] To a container with a stirrer, 634 g of4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolyl phenol, 52 g ofparaformaldehyde, 110 g of diethylamine and 600 ml of xylene werecharged, and reacted at a temperature of 95 to 100° C. for 24 hours.Then, 31 g of 28% sodium methylate solution in methanol was added andreacted at a temperature of 145 to 150° C. for 10 hours. Upon completionof the reaction, the reaction solution was washed with water, 100 ml ofmethyl isobutyl ketone was added to the xylene layer and crystallized.The resulting crystal was filtered to obtain 594.0 g (yield 92%) of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as white crystal (causing no dust) with a melting point of 199 to 200°C. The resulting compound had a mass of 659 (calculated value 658.9) inmass spectrometry. In addition, powder X-ray diffraction analysis withCu-Kα radiation indicated that the resulting crystal was a crystalmaterial having distinct diffraction peaks at diffraction angles(2θ±0.1°) of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and 23.0° as shown in FIG.1.

[0073] Further, the compaction degree of the resulting crystal was 30 inpowder test.

COMPARATIVE EXAMPLE 1 Preparation of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]according to conventional process

[0074] To a container with a stirrer, 634 g of4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolyl phenol, 52 g ofparaformaldehyde, 110 g of diethylamine and 600 ml of xylene werecharged, and reacted at a temperature of 95 to 100° C. for 24 hours.Then, 31 g of 28% sodium methylate solution in methanol was added andreacted at a temperature of 145 to 150° C. for 10 hours. Upon completionof the reaction, the reaction solution was washed with water, xylene wasdistilled off and crystallized from methanol to obtain 581.1 g (yield90%) of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as white crystal (causing dust) with a melting point of 199 to 200° C.The resulting compound had a mass of 659 (calculated value 658.9) inmass spectrometry. In addition, the compaction degree of the resultingcrystal was 48 in powder test, and suggested that the powder had a lowflowability.

EXAMPLE 2 Light Stabilization Effect for Polymer Material

[0075] 100 parts by weight of polyethylene powder or polypropylenepowder was thoroughly mixed in a mixer with 0.05, 0.2 or 0.5 part byweight of the compound prepared in Example 1 (dusts were not dischargedupon mixing) and the mixture was thereafter subjected to melt extrusionthrough an extruder with a cylinder temperature of 200° C. and adiameter of 25 mm to form pellets. The pellets were subjected tocompression molding into a shape of sheet at 210° C. to form test pieceshaving a thickness of 0.25 mm. Dumbbell specimens for tensile test werepunched out of the test pieces. Specimens without light stabilizers forcomparative examples were prepared in a similar manner as above andsubjected to measurement.

[0076] These specimens were irradiated in WEL-75XS-HS-BEC type XenonSunshine Long-Life Weather-O-Meter manufactured by Suga Test InstrumentCo., Ltd. at a black panel temperature of 80° C. and lowering in tensilestrength of each specimen with time was compared. The tensile test wasconducted at a temperature of 23±2° C., a relative humidity of 50±5% anda test rate of 50±5.0 mm/min. with DSS-5000 type tension testermanufactured by Shimadzu Corporation. Tension strength was determinedaccording to the equation below:

Ts=S/T·W

[0077] wherein Ts=tension strength (kgf/mm²),

[0078] T=thickness of a sample (mm),

[0079] W=width of a sample (mm), and

[0080] S=maximum strength of a sample (kgf).

[0081] The results are summarized in Table 1.

[0082] As clear from the results shown in Table 1, the low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to the present invention showsexcellent stabilization effect (that is, prolongation of time todeterioration). TABLE 1 (Unit: kgf) Amount of light stabilizer added (%200 400 600 800 1000 1200 Resin by weight) hrs. hrs. hrs. hrs. hrs. hrs.Polypropylene None 3.14 2.12 0 — — — 0.05 4.04 3.13 2.99 — — — 0.2 4.243.94 3.89 — — — 0.5 4.46 4.35 4.14 — — — Polyethylene None 2.41 2.252.24 2.10 1.89 0 0.05 3.36 3.26 3.14 3.07 3.03 2.84 0.2 3.94 3.76 3.543.48 3.42 3.22 0.5 4.46 4.26 4.12 3.92 3.80 3.72

[0083] II. Preparation and evaluation of low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation and mixture of type I crystaltransformation and type II crystal transformation

[0084] Condition and Method for Measurement

[0085] A mixing proportion of type II and type I was determined based onDSC measurements by using a calibration curve prepared from calorimetricratio of the exothermic peak of type II and the endothermic peak of typeI which were measured with respective pure crystal transformation.

[0086] The DSC measurements were conducted with TA Instrument Type 2920DSC under the condition of a sample amount of 1.3 mg, atmosphere in theoven of nitrogen flow with 50 ml/min., and a heating rate at 10.0°C./min.

[0087] In a similar manner as the above-mentioned I, powder X-raydiffraction analysis with Cu-Kα radiation was conducted with TFD-18kwmanufactured by Mac Science Co., Ltd. under the condition ofanti-cathode Cu-Kα (1.5405 Å), 40 kV-50 mA and a scanning rate at2.000°/min. In addition, a diffraction angle (2θ) in powder X-raydiffraction analysis for the same crystal form is identical with anerror of about ±0.1°, and therefore clearly indicates a difference incrystal transformation. The relative intensity of a diffractionradiation may effect change in the intensity ratio depending on theparticle diameter of the sample to be measured.

[0088] UV light absorbers were evaluated by subjecting a sample preparedby treating a dyed polyester fabric with a UV light absorber (anemulsion composition) to an exposure test for 300 hours and determiningdiscoloration or fading of the sample.

[0089] In the exposure test, Table Sun TS-1 manufactured by Suga TestInstrument Co., Ltd. was used.

COMPARATIVE EXAMPLE 2 Preparation of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]according to conventional process

[0090] To a container with a stirrer, 63.4 kg of4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolyl phenol, 5.2 kg ofparaformaldehyde, 11.0 kg of diethylamine and 60 L of xylene werecharged, and reacted at a temperature of 95 to 100° C. for 24 hours.Then, 3.1 kg of 28% sodium methylate solution in methanol was added andreacted under nitrogen gas at temperature of 145 to 150° C. for 10hours. The reaction solution was washed with water, and crystallized bycooling the xylene layer to 10° C. The resulting crystal was filtered toobtain 56.8 kg (yield 88%) of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]as white solid in a shape of fine powder (causing dust). Powder X-raydiffraction analysis for the resulting crystal with Cu-Kα radiationindicated that it was type I having distinct diffraction peaks atdiffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and23.0° as shown in FIG. 4. Further, DSC analysis indicated that thecrystal was 100% type I as shown in FIG. 5.

EXAMPLE 3 Preparation low dusting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation

[0091]2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in Comparative Example 2 was melted at a temperature of 220 to240° C. and cooled to 10° C. with a flaker to obtain crystal in a shapeof flake (causing no dust). Powder X-ray diffraction analysis for thecrystal obtained by grinding the resulting flake with Cu-Kα radiationindicated that it was type II which was amorphous and which did notexhibit distinct diffraction peak but a halo as shown in FIG. 2. In themeantime, the powder X-ray diffraction analysis indicated that thecrystal from Example 3 was 100% type II. Further, DSC analysis for 100%type II crystal transformation from Example 3 exhibited one exothermicpeak at 130.2° C. and one endothermic peak at 198.2° C. as shown in FIG.3.

EXAMPLE 4 Preparation of low dusting mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and type II crystal transformation

[0092]2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in a similar manner as Comparative Example 2 was melted at atemperature of 205 to 210° C. and cooled to 10° C. with a flaker toobtain crystal in a shape of flake (causing no dust). Powder X-raydiffraction analysis for the crystal obtained by grinding the resultingflake with Cu-Kα radiation indicated that it was type I having distinctdiffraction peaks at diffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°,16.1°, 18.1° and 23.0° as shown in FIG. 6. Further, from DSC analysisresult [a calorimetric ratio of endothermic peak of type I to exothermicpeak of type II was 75.7 (type I):24.3 (type II)] as shown in FIG. 7,the mixing proportion of type I crystal transformation and type IIcrystal transformation in the resulting flake was 51.0% by weight oftype I and 49.0% by weight of type II.

EXAMPLE 5 Preparation of low dusting mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and type II crystal transformation

[0093]2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in a similar manner as Comparative Example 2 was melted at atemperature of 210 to 215° C. and cooled to 10° C. with a flaker toobtain crystal in a shape of flake (causing no dust). Powder X-raydiffraction analysis for the crystal obtained by grinding the resultingflake with Cu-Kα radiation indicated that it was type I having distinctdiffraction peaks at diffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°,16.1°, 18.1° and 23.0° as shown in FIG. 8. Further, from DSC analysisresult [a calorimetric ratio of endothermic peak of type I to exothermicpeak of type II was 64.9 (type I):35.1 (type II)], the mixing proportionof type I crystal transformation and type II crystal transformation inthe resulting flake was 16.9% by weight of type I and 83.1% by weight oftype II.

EXAMPLE 6 Preparation of low dusting mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and type II crystal transformation

[0094]2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in a similar manner as Comparative Example 2 was melted at atemperature of 195 to 200° C. and cooled to 10° C. with a flaker toobtain crystal in a shape of flake (causing no dust). Powder X-raydiffraction analysis for the crystal obtained by grinding the resultingflake with Cu-Kα radiation indicated that it was type I having distinctdiffraction peaks at diffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°,16.1°, 18.1° and 23.0°. Further, from DSC analysis result [acalorimetric ratio of endothermic peak of type I to exothermic peak oftype II was 93.9 (type I):6.1 (type II)], the mixing proportion of typeI crystal transformation and type II crystal transformation in theresulting flake was 90.0% by weight of type I and 10.0% by weight oftype II.

FORMULATION EXAMPLE 1 Preparation of Emulsion Composition

[0095] Emulsion composition A was prepared by adding 25.0 parts byweight of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in Example 3, 7.5 parts by weight of sodiumdodecylbenzenesulfonate, 2.0 parts by weight of glycerin lauric acidmonoester, 1.0 part by weight of sodium laurylaminopropionate, 12.7parts by weight of propylene glycol and 0.2 part by weight ofchloroacetamide into 51.6 parts by weight of water under stirring with abead mill. Similarly, emulsion compositions B, C and D were prepared byadding2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in Example 4,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in Comparative Example 2 according to a conventional process,and no2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol],respectively, in place of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]obtained in Example 3.

FORMULATION EXAMPLE 2 Preparation of Evaluation Sample

[0096] Evaluation sample A was prepared by dipping a polyester fabricdyed with Kayalon Polyester Yellow BRL-S200 (trade name, manufactured byNippon Kayaku Co., Ltd.), Kayalon Polyester Navy Blue EX-SF200 (tradename, manufactured by Nippon Kayaku Co., Ltd.) and Kayalon PolyesterLight Scarlet G-S200 (trade name, manufactured by Nippon Kayaku Co.,Ltd.) in emulsion composition A prepared in Formulation Example 1,washing with water and drying. Similarly, evaluation samples B, C and Dwere prepared by using emulsion compositions B, C and D, respectively,in place of emulsion composition A.

EXAMPLE 7 Measurement of Resistance to Discoloration

[0097] Evaluation samples prepared in Formulation Example 2 weresubjected to an exposure test (Table Sun TS-1 manufactured by Suga TestInstruments Co., Ltd.) and level of discoloration and fading after UVlight irradiation of 300 hours was examined by visually comparing colorshade between a sample before irradiation and the sample afterirradiation. Fastness to light was evaluated as follows: no change(level 4), very tiny change (level 3), a little change (level 2) andapparent fading (level 1) wherein the more the level is, the higher thefastness to light is. The result are shown in Table 2. TABLE 22,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6- Level of Evaluationbenzotriazolyl phenol] added in emulsion fastness sample composition tolight A 100% type II product obtained in Example 3 4 B 49% type IIproduct obtained in Example 4 4 C 100% type I product obtained inComparative 3 Example 2 D None 1

EXAMPLE 8 Measurement of Light Stabilization Effect for Polymer Material

[0098] 100 parts by weight of polyethylene powder was thoroughly mixedin a mixer with 2.0 parts by weight of the compound prepared in Example3 (100% type II) and the mixture was thereafter subjected to meltextrusion through an extruder with a cylinder temperature of 180° C. anda diameter of 25 mm to form pellets. The pellets were subjected tocompression molding into a shape of sheet having a thickness of 0.25 mmat 180° C. Dumbbell specimens for tensile test were punched out of thesheets. Further, specimens containing the compound prepared inComparative Example 2 (100% type I) or no light stabilizer were preparedas control for comparison in a similar manner as above and subjected tomeasurement of light stabilization effect. Further, X-ray diffractionanalysis for these specimens indicated that the sheet prepared by usingthe compound prepared in Example 3 (100% type II) as light stabilizerexhibited no diffraction peak of the light stabilizer as shown in FIG. 9and indicated the same diffraction pattern as that of a sheet containingno light stabilizer. On the contrary, the diffraction pattern of thesheet produced by adding the compound prepared in Comparative Example 2(100% type I according to a conventional process) is shown in FIG. 10,and exhibits diffraction peaks at diffraction angles (2θ±0.1°) of 7.1°,8.6°, 14.3°, 16.1°, 18.1° and 23.0° which are characteristics of thecompound prepared in Comparative Example 2 (100% type I according to aconventional process).

[0099] These specimens were irradiated in Xenon Sunshine Long-LifeWeather-O-Meter at a black panel temperature of 80° C. and lowering intensile strength of each specimen with time was compared. The tensiletest was conducted at a temperature of 23±2° C., a relative humidity of50±5% and a test rate of 50±5.0 mm/min. Tension strength was determinedaccording to the equation below:

Ts=S/T·W

[0100] wherein Ts=tension strength (kgf/mm²),

[0101] T=thickness of a sample (mm),

[0102] W=width of a sample (mm), and

[0103] S=maximum strength of a sample (kgf).

[0104] The results are summarized in Table 3. TABLE 3 (Unit: kgf) 0 400800 1200 Light stabilizer hr. hrs. hrs. hrs. Example 3 4.69 4.51 3.953.77 (100% type II) Comparative Example (100% type I 4.35 4.10 3.21 2.23according to conventional process) None 4.65 2.41 1.80 0

[0105] As clear from the results shown in Table 3,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to the present invention showsmore excellent stabilization effect (that is, prolongation of time todeterioration) than the type I crystal transformation according to theconventional process.

[0106] As mentioned above,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation and II crystal transformation, and acrystal transformation mixture comprising the type II crystaltransformation in an amount of 1% by weight or more based on the amountof the type I crystal transformation, which are prepared according tothe present invention, cause little dust and are UV light absorberseffective for working environment.

1. A low dusting crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation of formula (1)

which exhibits diffraction peaks at diffraction angles (2θ±0.1°) of7.1°, 8.6°, 14.3°, 16.1°, 18.1° and 23.0° in powder X-ray diffractionanalysis with Cu-Kα radiation.
 2. The crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to claim 1, which has acompaction degree of 35 or less in powder test.
 3. A method forpreparing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to claim 1 or 2, characterizedby crystallizing2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]in the presence of ketone. 4.2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation of formula (1)

characterized in that does not exhibit a distinct diffraction peak but ahalo in powder X-ray diffraction analysis with Cu-Kα radiation and thatis amorphous.
 5. A mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]comprising2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation which exhibits diffraction peaks atdiffraction angles (2θ±0.1°) of 7.1°, 8.6°, 14.3°, 16.1°, 18.1° and23.0° in powder X-ray diffraction analysis with Cu-Kα radiation, and the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to claim 4 in an amount of 1%by weight or more based on the amount of the type I crystaltransformation.
 6. A mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]comprising the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to claim 1 or 2, and the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to claim 4 in an amount of 1%by weight or more based on the amount of the type I crystaltransformation.
 7. A method for preparing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to claim 4, characterized bymelting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]at a temperature of 195° C. or more, and cooling and solidifying.
 8. Amethod for preparing the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]according to claim 5 or 6, characterized by melting2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]at a temperature of 195° C. or more, and cooling and solidifying.
 9. AUV light absorber characterized by containing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to claim 1 or
 2. 10. An emulsioncomposition characterized by containing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to claim 1 or
 2. 11. A polymermaterial characterized by containing the crystalline2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type I crystal transformation according to claim 1 or 2 or the emulsioncomposition according to claim
 10. 12. A UV light absorber characterizedby containing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to claim
 4. 13. An emulsioncomposition characterized by containing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to claim
 4. 14. A polymermaterial characterized by containing the2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]type II crystal transformation according to claim 4 or the emulsioncomposition according to claim
 13. 15. A UV light absorber characterizedby containing the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]according to claim 5 or
 6. 16. An emulsion composition characterized bycontaining the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]according to claim 5 or
 6. 17. A polymer material characterized bycontaining the mixture of2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazolylphenol]according to claim 5 or 6 or the emulsion composition according to claim16.